Radiation and diffusion effects on MHD Sisko fluid flow over a nonlinearly stretchable porous sheet

This study investigates the behavior of a magneto-Sisko fluid in a two-dimensional domain influenced by a nonlinearly stretchable sheet within a porous medium. The analysis considers the effects of a uniform magnetic field, thermal radiation, and heat generation while incorporating Brownian motion and thermophoresis diffusion. The governing nonlinear partial differential equations are transformed into ordinary differential equations through similarity transformation and solved using the Newton-Raphson shooting method coupled with the Runge-Kutta-Fehlberg (RKF45) algorithm. The findings reveal that increasing the Sisko fluid parameter enhances velocity profiles while reducing both temperature and concentration distributions. For instance, when the Sisko parameter is increased from 1.0 to 2.0, the velocity profile rises by approximately 18 %, whereas the temperature and concentration profiles decrease by 12 % and 9 %, respectively. Furthermore, higher values of the power-law exponent and the nonlinear stretching coefficient leads to reduced velocity, temperature, and concentration. Specifically, for a power-law index increasing from 1.2 to 1.8, the velocity declines by 15 %, while temperature and concentration decrease by 10 % and 7 %, respectively. The presence of thermal radiation elevates the temperature profile by nearly 22 %, emphasizing its role in energy transport. These findings are in agreement with previous studies, underscoring the complex interplay of magnetic fields, viscosity variations, and heat diffusion mechanisms in shaping the fluid dynamics. The results offer valuable insights into optimizing industrial applications such as polymer extrusion, metallurgical processes, and chemical engineering systems.